{
  "abstract": "A 55-year-old woman presented to the hospital with 14 days of chest pain, shortness of breath and low fever. She had a 10-year history of primary Sjögren’s syndrome (pSS). Laboratory testing revealed immunoglobulin IgG 2780 mg/dL (normal range 694–1620), IgG4 348 mg/dL (normal range 3–201). Additionally, her C reactive protein (CRP) was elevated at 1.48 mg/dL (normal <0.8 mg/dL) before treatment. Antinuclear antibodies were positive with a 1:320 titre (normal range <1:80) in a speckled pattern. Anti-SSA and anti-Ro-52 antibodies were positively identified through immunoblotting. She was also tested for myositis-specific antibodies, including those related to anti-synthetase syndrome and anti-MDA5 dermatomyositis, all of which returned negative. Chest CT showed ground glass opacity and consolidation in both lungs, and a small amount of pleural effusion ( figure 1A, axial view). The imaging diagnosis was more consistent with an organising pneumonia (OP) pattern. Pleural effusion was exudative and mainly contained multinucleated cells; no cancer cells were found. Percutaneous lung puncture biopsy samples showed the alveolar septum was widened, a large number of plasma cells and a small number of T lymphocytes were found in the interstitium, and lung tissue structure was preserved (figure 1C, inset showing plasma cells aggregation; H&E stain). Immunohistochemistry revealed that multiple myeloma oncogene 1 (MUM1) was focally expressed (figure 1D), and MUM1 is a nuclear marker seen in activated B cells and plasma cells. IgG was scattered and IgG4 was sporadically expressed in lung tissue. Thus, a diagnosis of pSS combined with cellular non-specific interstitial pneumonia (NSIP) was made. The patient was treated with methylprednisolone (40 mg/day for 2 weeks, then tapered regularly), azathioprine (50 mg two times per day). By 1 week after the initiation of treatment, the radiographic findings had greatly improved (figure 1B), and her CRP had normalised. The associated symptoms did not recur, and repeat chest CT after 1 year of follow-up did not suggest progression of the lesions. Although a pretreatment baseline pulmonary function test is unavailable, pulmonary function tests at the 1-year follow-up were within the normal range.",
  "authors": [
    {
      "affiliations": [
        "Department of Rheumatology, China-Japan Friendship Hospital, Beijing, China"
      ],
      "name": "Yu Zuo"
    },
    {
      "affiliations": [
        "Department of Pathology, China-Japan Friendship Hospital, Beijing, China"
      ],
      "name": "Jie Tong"
    },
    {
      "affiliations": [
        "Department of Rheumatology, China-Japan Friendship Hospital, Beijing, China"
      ],
      "name": "Xin Lu"
    }
  ],
  "title": "Lung consolidation as a presentation of primary Sjögren’s syndrome",
  "uid": "678e9171-840c-5cc1-8576-e5c5ebeffb49"
}